USDA Forest Service

Deschutes & Ochoco National Forests
Crooked River National GrasslandHeader Counter


Deschutes National Forest
1001 SW Emkay Drive
Bend, OR   97702

(541) 383-5300

Ochoco National Forest
3160 N.E. 3rd Street
Prineville, OR   97754

(541) 416-6500

Crooked River National Grassland
813 S.W. Hwy. 97
Madras, OR   97741

(541) 475-9272

United States Department of Agriculture Forest Service.


Oregon Volcanoes

Four Craters Flows


Type: lava flow field
Activity: extinct
Last Eruption: less than 50,000 years ago
Rock Type: basalt
Eruptive Volume: ?
Latitude: 43.37 N
Longitude: 120.67 W
Location Maps: from TIGER Mapping Service

Topo Map from TopoZone

Four Craters Photo Menu


The Four Craters field covers about 30 square kilometers. Four Pleistocene cinder cones are the source of the flows in the field and are aligned along a fissure trending N 30° W. The cones rise 75 to 120 meters above the flows and the distance beween the northern most and southern most cones is about 3.5 kilometers.

Closely related to the Four Craters lava field is Crack-in-the-Ground located at the southwest corner of the field. The eruptions from the field were accompanied by a slight sinking of the older rock surface. This shallow, graben-like sink is about 3 kilometers wide and extends to the south into an old lake basin. Crack-in-the-Ground marks the western edge of this small, volcano-tectonic depression and is nearly 9 meters deep and over a meter wide. The crack is the result of a tension fracture along a hingeline produced by the drapping of Green Mountain lava flows over the edge of upthrown side of the concealed fault zone.


  • None


  • Jensen, 1995.



Geology Header Graphic
Page Counter

USDA Forest Service - Deschutes & Ochoco National Forests
Last Modified: Wednesday, 24 December 2003 at 17:09:43 EST

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.